Short Answer
Deep Model Processing does not geometrically recalculate areas: when you upload an IFC model, vyzn adopts the area and volume values stored on the rooms in the model and aggregates them via the room classification. For area evaluation, vyzn follows the SIA 416:2003 system; the energy reference area (EBF) is determined separately, exclusively via the SIA 380:2015 classification.
Why It Matters
The aggregated areas form the basis of your energy and life cycle assessment evaluations: the EBF serves as the reference value for the per-m² indicators in the life cycle assessment. For the area aggregation to work, the rooms in the IFC must be classified and carry area values — if either is missing, the area aggregation cannot calculate. It is therefore worth knowing where the values come from and how they are assigned.
How It Works in vyzn
Deep Model Processing: When you upload an IFC model, the AI-based Deep Model Processing handles the file asynchronously in the background. It reads the IFC structure and extracts building elements, rooms and their property sets. For each room, vyzn adopts in particular the gross area and the volume, as well as information such as whether a room lies below ground. Together with the reference area values — including gross, net and room area at element level — these values flow into the model version. vyzn therefore does not recalculate areas geometrically, but adopts the area values present in the model and then aggregates them via the room classification.
Area system according to SIA 416:2003: Rooms are assigned to categories via their classification and summed hierarchically. Each parent category is the sum of its subcategories:
- Plot area (GSF) with building footprint area (GGF) and surrounding area (UF), split into developed (BUF) and undeveloped surrounding area (UUF)
- Floor area (GF) with net floor area (NGF) and construction area (KF)
- Net floor area (NGF) with usable area (NF, split into main usable area HNF and secondary usable area NNF), circulation area (VF) and functional area (FF)
- In addition, the building volume (GV) is tracked
Energy reference area (EBF): The EBF is determined exclusively via the SIA 380:2015 classification and deliberately not derived from SIA 416 rooms. This keeps the EBF, which serves as the reference value for the per-m² indicators in the life cycle assessment, cleanly separated.
Fallback for older models: In addition, vyzn can take an older room-type classification into account. It serves as a fallback for SIA 416 if a model has not yet been migrated to the SIA 416 classification.
Frequently Asked Questions
Does vyzn calculate the areas itself from the geometry?
No. vyzn adopts the area values stored in the IFC model and aggregates them via the room classification — no geometric recalculation takes place.
Why is the EBF not derived from the SIA 416 areas?
To keep the EBF cleanly separated as the reference value for the per-m² indicators in the life cycle assessment, it is determined exclusively via the SIA 380:2015 classification.
What must be present in the IFC model?
The rooms in the IFC must be classified and carry area values. If either is missing, the area aggregation cannot calculate.
What if my model still uses the old room-type classification?
It then serves as a fallback for SIA 416. If needed, we are happy to look together with you at how your specific models are classified and which area indicators you need.
Update (version 1.8.5)
As of version 1.8.5, Deep Model Processing is no longer incorrectly skipped, and the underlying IFC processing was updated to version 1.4.3 – this improves the detection of components and area values from your model.